Smart sensor devices for measuring and verifying solar array performance and operational methods for use therewith

ABSTRACT

A device comprises a platform constructed and arranged to be mounted to one or more solar array modules and one or more solar irradiance sensors on the platform configured to receive incident solar energy, the one or more solar irradiance sensors oriented on the platform so that the received incident solar energy is comparable to that received by the solar array modules, the one or more solar irradiance sensors providing solar irradiance signals in response to the incident solar energy. A processor is on the platform, the processor configured to receive the solar irradiance signals and, in response, generating a performance reference metric based on the solar irradiance signals, the performance reference metric related to the expected performance of the one or more solar array modules to which the platform is mounted. A transmitter is on the platform, the transmitter configured to periodically transmit the performance reference metric to a receiver.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 15/980,010, filed on May 15, 2018, which is acontinuation application of U.S. patent application Ser. No. 15/030,964,filed on Apr. 21, 2016, which issued on Jun. 5, 2018 as U.S. Pat. No.9,991,844, which is a 371 of International Application No.:PCT/US2014/0065653, filed Nov. 14, 2014, which claims the benefit ofU.S. Provisional Patent Application No. 61/904,169, filed on Nov. 14,2013, the entire content of which is incorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates to monitoring systems for solar andenergy systems, and, more particularly, to a smart sensor device for asolar system, a system that incorporates the smart sensor device, andoperational methods for gauging performance of, or simulating the outputof, solar energy systems.

Discussion of Related Art

Referring to FIG. 1, traditional weather monitoring hardware systems formonitoring efficiency of solar systems experience limitations due tohigh cost, non-standardized installation and operations, andinconsistent performance calculations and methods. Traditional weatherstations typically are large standalone structures 10 located atpositions away from the solar array modules 12 being monitored andrequire a source of power and/or communications lines. Limitations ofsuch weather stations include high cost, making them almost non-existentin residential and small commercial applications due to price factors,non-standardization, meaning that vendors install and configure theseunits in non-standardized ways, and lack of packaging that accounts forreal-world conditions such as snow and dirt.

SUMMARY

Embodiments of the present inventive concepts provide smart sensordevices that can provide an improved platform for gauging performance ofsolar energy systems. Embodiments of the present inventive conceptsfurther provide methods for using and controlling smart sensor devicesthat can provide an improved platform for gauging performance of, orsimulating the output of, solar energy systems. Other applications ofthe present inventive concepts can include providing a service toutilities for managing power distribution.

In accordance with exemplary embodiments of the present inventiveconcepts, environmental sensing, processing and transmitting based smartsensor devices, and operational methods therewith, provide such neededimproved platform for gauging performance of solar energy systems.

In exemplary embodiments, smart sensor devices configured in accordancewith the present inventive concepts mimic the physiology of a workingsolar energy system for the purpose of providing a reference point forgauging performance.

In exemplary embodiments, smart sensor devices can optionally includetheir own power supply and wireless communications systems.

In one aspect, a device comprises: a platform constructed and arrangedto be mounted to one or more solar array modules: one or more solarirradiance sensors on the platform configured to receive incident solarenergy, the one or more solar irradiance sensors oriented on theplatform so that the received incident solar energy is comparable tothat received by the solar array modules, the one or more solarirradiance sensors providing solar irradiance signals in response to theincident solar energy; a processor on the platform, the processorconfigured to receive the solar irradiance signals and, in response,generating a performance reference metric based on the solar irradiancesignals, the performance reference metric related to the expectedperformance of the one or more solar array modules to which the platformis mounted; and a transmitter on the platform, the transmitterconfigured to periodically transmit the performance reference metric toa receiver.

In some embodiments, the device further comprises a temperature sensorthat provides a device temperature signal and wherein the processorfurther generates the performance reference metric based on the devicetemperature signal.

In some embodiments, the processor further generates the performancereference signal based on a cell temperature signal that is calculatedin response to the device temperature signal and the solar irradiancesignals.

In some embodiments, the temperature sensor generates the devicetemperature signal periodically.

In some embodiments, the processor further generates the performancereference metric based on a dynamic derate value that is calculatedbased on an efficiency function of an inverter of the solar arraymodules in response to the solar irradiance signals.

In some embodiments, the efficiency function is non-linear.

In some embodiments, the processor further generates the performancereference metric based on a static value that is calculated based on anestimate of expected power loss in the solar array.

In some embodiments, the processor further compares the generatedperformance reference metric to a maximum value, and if the generatedperformance reference metric exceeds the maximum value, the generatedperformance related metric is set to the maximum value, the maximumvalue being determined in response to a known maximum AC power rating ofthe solar array modules.

In some embodiments, the processor further generates the performancereference metric based on a cumulative irradiance value, the cumulativeirradiance value being based on multiple ones of the solar irradiancesignals accumulated over a time period.

In some embodiments, the processor further generates the performancereference metric as a cumulative performance related matric based onmultiple ones of the generated the performance reference metricaccumulated over a time period.

In some embodiments, the time period over which the performancereference metrics are accumulated is one hour.

In some embodiments, the transmitter is further configured to transmitthe performance reference metric periodically in response to a mode ofoperation, the mode of operation being determined in response to thetime of day.

In some embodiments, the mode of operation results in more frequenttransmission during a time of day where more intense sun exposure isexpected and results in less frequent transmission during a time of daywhen less intense or no sun exposure is expected.

In some embodiments, the processor is further configured to generate theperformance reference metric periodically in response to a mode ofoperation, the mode of operation being determined in response to thetime of day.

In some embodiments, the mode of operation results in more frequentgeneration of the performance reference metric during a time of daywhere more intense sun exposure is expected and results in less frequentgeneration of the performance reference metric during a time of day whenless intense or no sun exposure is expected.

In some embodiments, a portion of the platform is constructed andarranged to be positioned on a top surface of the one or more solarpanels, the portion having a maximum width in a first horizontaldirection and having a maximum height above the top surface in avertical direction, wherein the maximum width is greater than or equalto two times the maximum height.

In some embodiments, a portion of the platform is constructed andarranged to be positioned on a top surface of the one or more solarpanels, the portion having a maximum width in a first horizontaldirection and having a maximum height above the top surface in avertical direction, wherein the maximum width is greater than or equalto three times the maximum height.

In some embodiments, the platform comprises a circuit board and whereinsolar irradiance sensor comprises a pyranometer, the pyranometercomprising: a diffuser for receiving incident solar energy, the diffuserhaving an inner chamber; and a photodiode positioned in the innerchamber for converting the solar energy received by the diffuser into acurrent signal; wherein the inner chamber is of a sufficient height toaccommodate a maximum height of a photodiode selected among a pluralityof photodiode types; and wherein the inner chamber is of a sufficientwidth to accommodate a maximum width of a photodiode selected among aplurality of photodiode types.

In some embodiments, the circuit board includes a photodiode padincluding a plurality of conductive pads for mounting any among theplurality of photodiode types.

In some embodiments, the platform further comprises a power source forpowering the processor and the transmitter.

In some embodiments, the power source comprises a solar collector on theplatform and a power storage element for storing energy collected by thesolar collector.

In some embodiments, the power storage element comprises a supercapacitor.

In some embodiments, the solar collector and storage element comprisesthe exclusive power source for the device.

In some embodiments, the device further comprises a supplementalbattery.

In some embodiments, the processor is configured to further receivesignals from a third-party sensor for calibration of the one or moresolar irradiance sensors.

In another aspect, a smart sensor device for performance measurement andverification of a solar array having one or more solar panels, the smartsensor device comprises: a device platform configured to be mounted onone or more solar array modules; one or more irradiance sensor devicesconfigured to be mounted on the device platform such that the one ormore irradiance sensor devices receive solar irradiance comparable tothat received by a solar panel of the solar array; a temperature sensorconfigured to be mounted on the device platform such that thetemperature sensor is used to calculate a solar module temperature atthe solar array; and a processor, within the smart sensor device,configured to process data corresponding to the solar irradiance and anambient temperature received by the smart sensor device and to transmitperformance monitoring data to a data monitoring user.

In some embodiments, the irradiance sensor device is mounted between apair of solar panels.

In some embodiments, the irradiance sensor device comprises apyranometer.

In some embodiments, the one or more irradiance sensor devices aremounted on one side of the device platform such that primary solarirradiance receiving surfaces of the irradiance sensor devices aresubstantially parallel to the solar panels, and the temperature sensoris mounted on an opposing side of the device platform.

In some embodiments, the smart sensor device further comprises a devicesolar panel mounted on the device platform configured to provide powerto operate the smart sensor device.

In some embodiments, the smart sensor device further comprises a batterypack to provide supplemental power to operate the smart sensor device.

In some embodiments, the performance monitoring data is transmitted to adata monitoring user using standardized transmission protocols.

In some embodiments, the performance monitoring data is transmitted by atransceiver located within the smart sensor device.

In some embodiments, the performance monitoring data is transmittedusing Zigbee protocol wireless radio transceivers.

In some embodiments, the processor is mounted in a secondary deviceplatform coupled to the device platform.

In some embodiments, the smart sensor device operates in two or moremodes of operation in view of time of operation.

In some embodiments, the modes of operation comprise a daylight mode, atwilight mode and a night mode.

In some embodiments, data is processed and resulting performancemonitoring data is transmitted to a data monitoring user according tothe following equation:

${{Denowatts}^{}\mspace{11mu} {metric}} = {\sum_{1}^{n}{( \frac{{{Irr}({Pdc})}( {1 + {\alpha ( ( {{Tcell} - 25} ) )}} )}{( \frac{1}{n} )(8600)(1000)} )( {{Derate}\mspace{14mu} {Factor}} )}}$

wherein:

${{Denowatts}^{}\mspace{11mu} {metric}} \leq {{Pac}/( {\frac{1}{n}*3600} )}$ELSE${{Denowatts}^{}\mspace{11mu} {metric}} = {{Pac}/( {\frac{1}{n}*3600} )}$

and wherein:n: Time sample interval (seconds)

Irr: Computed Irradiance Measurement

Pdc: DC Power Rating of the solar arrayPac: Maximum Output AC Power Rating of the solar array

α: Reference Module Temperature Coefficient (Power)

Tcell: Calculated Solar Cell Temperature may be calculated as

Tcell=(Tdevice)(δ(Irr)+ε)

wherein:

-   -   Tdevice: Device temperature recorded on the device platform    -   δ and ε: calculated constants related to a reference cell

Static and Dynamic Derate Factors

Derate Factor=β(γ)

wherein:

β: Static Derate Factor

γ: Dynamic Derate Factor described by one or more polynomial equation(s)derived from the operating efficiency of a reference inverter and othersystem characteristics relative to irradiance conditions.

In another aspect, a method for performance monitoring of a solar arraycomprises: mounting a smart sensor device on one or more solar arraymodules, the smart sensor device being configured to receive solarirradiance and ambient temperature; processing, within the smart sensordevice, data corresponding to the solar irradiance and ambienttemperature received by the smart sensor device to provide performancemonitoring data; and transmitting the performance monitoring data to aremote data monitoring user or a remote data services supplier.

In some embodiments, the method further comprises mounting the smartsensor device between a pair of solar panels.

In some embodiments, smart sensor device comprises a pyranometer.

In some embodiments, the method further comprises mounting a one or moreirradiance sensor devices on one side of a device platform such thatprimary solar irradiance receiving surfaces of the irradiance sensordevices are substantially parallel to the solar panels, and mounting atemperature sensor on an opposing side of the device platform.

In some embodiments, the method further comprises mounting a devicesolar panel on the device platform to provide power to operate the smartsensor device.

In some embodiments, the method further comprises providing a batterypack to provide supplemental power to operate the smart sensor device.

In some embodiments, the method further comprises transmitting theperformance monitoring data to the data monitoring user usingstandardized transmission protocols.

In some embodiments, the method further comprises transmitting theperformance monitoring data by a transceiver located within the smartsensor device.

In some embodiments, the method further comprises transmitting theperformance monitoring data using Zigbee protocol wireless radiotransceivers.

In some embodiments, the method further comprises mounting the processorin a secondary device platform coupled to the device platform.

In some embodiments, the method further comprises operating the smartsensor device in two or more modes of operation in view of time ofoperation

In some embodiments, the modes of operation comprise a daylight mode, atwilight mode and a night mode.

In some embodiments, processing data and transmitting resultingperformance monitoring data to a data monitoring user is according tothe following equation:

${{Denowatts}^{}\mspace{11mu} {metric}} = {\sum_{1}^{n}{( \frac{{{Irr}({Pdc})}( {1 + {\alpha ( ( {{Tcell} - 25} ) )}} )}{( \frac{1}{n} )(8600)(1000)} )( {{Derate}\mspace{14mu} {Factor}} )}}$

wherein:

${{Denowatts}^{}\mspace{11mu} {metric}} \leq {{Pac}/( {\frac{1}{n}*3600} )}$ELSE${{Denowatts}^{}\mspace{14mu} {metric}} = {{Pac}/( {\frac{1}{n}*3600} )}$

and wherein:n: Time sample interval (seconds)Irr: Computed Irradiance Measurement (computed above)Pdc: DC Power Rating of the solar arrayPac: Maximum Output AC Power Rating of the solar array

α: Reference Module Temperature Coefficient (Power)

Tcell: Calculated Solar Cell Temperature may be calculated as

Tcell=(Tdevice)(δ(Irr)+ε)

wherein:

-   -   Tdevice: Device temperature recorded on the device platform    -   δ and ε: calculated constants related to a reference cell

Static and Dynamic Derate Factors

Derate Factor=β(γ)

wherein:

β: Static Derate Factor

γ: Dynamic Derate Factor described by one or more polynomial equation(s)derived from the operating efficiency of a reference inverter and othersystem characteristics relative to irradiance conditions.

In some embodiments, the processing of data further comprises:calculating and accumulating a total amount of Sun-Hours collected froman integral of irradiance data; and storing and transmitting the totalamount of Sun-Hours to the remote data monitoring user.

In some embodiments the method further comprises: receiving by the smartsensor device from a remote data monitoring user or from a remote dataservices provider configuration adjustment data such that one or more ofthe following can be adjusted at the smart sensor device: componentcalibration, simulation parameters, instruction code, and sensor driftof an irradiance sensor of the smart sensor device, and processing bythe smart sensor device the configuration adjustment data to update thesmart sensor device.

In some embodiments, an adjustment of sensor drift of the irradiancesensor comprises updating irradiance sensor voltage gain and offset.

In another aspect, a non-transitory computer program storage deviceembodying instructions executable by a processor to perform performancemonitoring of a solar array comprises: instruction code for processingdata corresponding to solar irradiance and ambient temperature receivedby a smart sensor device mounted on a solar array module to providesolar array performance monitoring data; and instruction code fortransmitting the solar array performance monitoring data to a remotedata monitoring user or remote date services supplier.

In another aspect, a solar simulator for generating reference data of asolar array, comprises: a processor configured to process data receivedby a solar irradiance sensor and a temperature sensor, the processorbeing mounted on the solar array proximal to solar panels of the solararray, wherein the data processed is configured to provide referencedata characteristics for measuring the performance of the solar array.

In some embodiments, the reference data characteristics are configuredto compare the performance of a second solar array with the performanceof the solar array.

In another aspect, a solar irradiance sensor device comprises: adiffuser configured to receive and condition light; at least onephotodiode configured to convert light into voltage; and a circuit boardconfigured to mount one or more photodiodes having different frequencyresponse characteristics, wherein the diffuser is mountable over the oneor more photodiodes such that a height of the solar irradiance sensordevice is less than a width of the solar irradiance sensor device.

In some embodiments, the frequency response characteristics of multiplephotodiodes are calculated to provide broadband spectral response data.

In some embodiments, a height of the solar irradiance sensor device isless than three times the width of a platform upon which the solarirradiance sensor device is mounted.

In another aspect, a self-powered solar sensor device, comprises: adevice platform configured to be mounted on one or more solar arraymodules; one or more irradiance sensor devices configured to be mountedon the device platform such that the one or more irradiance sensordevices receive solar irradiance comparable to that received by a solarpanel of the solar array; a temperature sensor configured to be mountedon the device platform such that the temperature sensor determines theambient temperature at the solar array; a processor, within the smartsensor device, configured to process data corresponding to the solarirradiance and the ambient temperature received by the smart sensordevice and to transmit performance monitoring data to a remote datamonitoring user or a remote data services supplier; and an internalpower source configured to power the self-powered solar sensor devicewithout a need for an external power source.

In some embodiments, the irradiance sensor device is mounted between apair of solar panels.

In some embodiments, the irradiance sensor device comprises apyranometer.

In some embodiments, the one or more irradiance sensor devices aremounted on one side of the device platform such that primary solarirradiance receiving surfaces of the irradiance sensor devices aresubstantially parallel to the solar panels, and the temperature sensoris mounted on an opposing side of the device platform.

In some embodiments, the self-powered sensor device further comprises adevice solar panel mounted on the device platform configured to providepower to operate the smart sensor device.

In some embodiments, the self-powered sensor device further comprises abattery pack to provide supplemental power to operate the smart sensordevice.

In some embodiments, the performance monitoring data is transmitted tothe remote data monitoring user or to the remote data services supplierusing standardized transmission protocols.

In some embodiments, the performance monitoring data is transmitted by atransceiver located within the smart sensor device.

In some embodiments, the performance monitoring data is transmittedusing Zigbee protocol wireless radio transceivers.

In some embodiments, the processor is mounted in a secondary deviceplatform coupled to the device platform.

In some embodiments, the smart sensor device operates in two or moremodes of operation in view of time of operation.

In some embodiments, the modes of operation comprise a daylight mode, atwilight mode and a night mode.

In some embodiments, data is processed and resulting performancemonitoring data is transmitted to the data monitoring user or to thedata services supplier according to the following equation:

${{Denowatts}^{}\mspace{11mu} {metric}} = {\sum_{1}^{n}{( \frac{{{Irr}({Pdc})}( {1 + {\alpha ( ( {{Tcell} - 25} ) )}} )}{( \frac{1}{n} )(8600)(1000)} )( {{Derate}\mspace{14mu} {Factor}} )}}$

wherein:

${{Denowatts}^{}\mspace{11mu} {metric}} \leq {{Pac}/( {\frac{1}{n}*3600} )}$ELSE${{Denowatts}^{}\mspace{14mu} {metric}} = {{Pac}/( {\frac{1}{n}*3600} )}$

and wherein:n: Time sample interval (seconds)Irr: Computed Irradiance Measurement (computed above)Pdc: DC Power Rating of the solar arrayPac: Maximum Output AC Power Rating of the solar array

α: Reference Module Temperature Coefficient (Power)

Tcell: Calculated Solar Cell Temperature may be calculated as

Tcell=(Tdevice)(δ(Irr)+ε)

wherein:

-   -   Tdevice: Device temperature recorded on the device platform    -   δ and ε: calculated constants related to a reference cell

Static and Dynamic Derate Factors

Derate Factor=β(γ)

wherein:

β: Static Derate Factor

γ: Dynamic Derate Factor described by one or more polynomial equation(s)derived from the operating efficiency of a reference inverter and othersystem characteristics relative to irradiance conditions.

In some embodiments, the processor is further configured to receive fromthe remote data monitoring user or from the remote data servicesprovider configuration adjustment data such that one or more of thefollowing can be adjusted at the smart sensor device: componentcalibration, simulation parameters, instruction code, and sensor driftof an irradiance sensor of the smart sensor device, and to process theconfiguration adjustment data to update the smart sensor device.

In some embodiments, an adjustment of sensor drift of the irradiancesensor comprises updating irradiance sensor voltage gain and offset.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of embodimentsof the present inventive concepts will be apparent from the moreparticular description of exemplary embodiments, as illustrated in theaccompanying drawings in which like reference characters refer to thesame elements throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the exemplary embodiments.

FIG. 1 depicts a typical weather station for monitoring a solar array.

FIGS. 2A, 2B, 2C, 2D, 2E(1), 2E(2), 2E(3), 2F, 2G and 2H are variousviews of smart sensor devices in accordance with exemplary embodimentsof the present inventive concepts.

FIGS. 3A and 3B are top and top perspective views respectively of asmart sensor device mounted between solar panels in accordance with anexemplary embodiment of the present inventive concepts.

FIG. 4A is a simplified overview processing flow diagram in accordancewith an exemplary embodiment of the present inventive concepts.

FIG. 4B is a simplified overview processing flow diagram of a Denowatts™metric calculation, in accordance with an exemplary embodiment of thepresent inventive concepts.

FIG. 5 depicts data logic and data flow in accordance with an exemplaryembodiment of the present inventive concepts.

FIG. 6 depicts various communication modes in accordance with exemplaryembodiments of the present inventive concepts.

FIGS. 7A and 7B depict various power supplying approaches in accordancewith exemplary embodiments of the present inventive concepts.

FIG. 8 is a table of sampling, logging and reporting times for variouscommunication modes for daylight, twilight and dark modes in accordancewith exemplary embodiments of the present inventive concepts.

FIG. 9 depicts a representative processing system in accordance with anexemplary embodiment of the present inventive concepts.

FIGS. 10A, 10B, 10C, 10D, 10E, 10F and 10G depict various aspects ofirradiance sensor devices in accordance with exemplary embodiments ofthe present inventive concepts.

FIGS. 11A, 11B and 11C are top-perspective, side and top viewsrespectively of an embodiment of the device platform, in accordance withthe present inventive concepts.

FIG. 12 is a chart of non-linear efficiency of a system inverter inresponse to system irradiance, in accordance with the present inventiveconcepts.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Various exemplary embodiments will be described more fully hereinafterwith reference to the accompanying drawings, in which some exemplaryembodiments are shown. The present inventive concepts may, however, beembodied in many different forms and should not be construed as limitedto the exemplary embodiments set forth herein.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numerals refer to likeelements throughout. As may be used herein, the term “and/or” includesany and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present inventive concepts.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element's or feature's relationship to another element(s)or feature(s) as illustrated in the figures. It will be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the example term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexemplary embodiments only and is not intended to be limiting of thepresent inventive concepts. As used herein, the singular forms “a,” “an”and “the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Exemplary embodiments may be described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized exemplary embodiments (and intermediate structures). As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments should not be construed as limitedto the particular shapes of regions illustrated herein but are toinclude deviations in shapes that result, for example, frommanufacturing. Thus, the regions illustrated in the figures areschematic in nature and their shapes are not intended to illustrate theactual shape of a region of a device and are not intended to limit thescope of the present inventive concepts.

The smart sensor devices and methods in accordance with exemplaryembodiments of the present inventive concepts provide a streamlinedsolution for solar performance benchmarking. In some embodiments, suchdevices and methods are constructed and arranged to communicate withmonitoring platforms via communication protocols, for examplestandardized transmission protocols and provide information to amonitoring user comparing desired solar performance versus actual solarperformance.

In some embodiments, smart sensor devices in accordance with the presentinventive concepts can include one or more of plane of array (POA)irradiance sensors and module cell temperature sensors. Solar arrayenergy production can be simulated. Wireless communication (includinggreater than 800 feet in urban conditions) can be provided. Energyharvesting technology allows the smart sensor devices to beself-powered. The smart sensor devices may be configured such that “dropin” installations (fitting in the gap between two solar array modules)can be provided. A receiver/gateway can be readily installed in thevicinity of the 800 foot range smart sensor devices for communicationwith third-party monitoring. The smart sensor devices can be remotelymanaged to ensure optimum reliability and accuracy. The smart sensordevices can be licensed as a service to deliver needed monitoringinformation without the hassle of hardware management.

In exemplary embodiments the smart sensor devices can captureenvironmental conditions such that it simulates a reference solar array.In some embodiments, the smart sensor devices can operate in a daylightmode, a twilight mode and a night mode to avoid a necessity ofprocessing excess data. During daylight conditions the smart sensordevice logs POA irradiance data via one or more pyranometer type units,as well as a calculated module cell temperature. Measurement samples canbe taken periodically, for example every 5 seconds, and logged asaverage POA irradiance, cell temperature and KWh equivalent (aDenowatts™ calculation) calculated periodically, for example eachminute, made into a record with irradiance and temperature periodically,for example each minute, simulating the physiology of a reference solararray (Denowatts™ is a trademark of PowerOwners). In some embodimentsdata can be transmitted periodically, for example every 5 minutes to areceiver/gateway.

In exemplary embodiments, the Denowatts™ metric calculation can includea simulated energy generation value which is analogous toKilowatt-Hours, representing a reference solar array. Calculations areperformed in the smart sensor devices using an embedded processor. FogComputing (a paradigm that extends Cloud computing and services to theedge of the network and provides data, compute, storage, and applicationservices to end-users) can be performed at the smart sensor device,which in turn can significantly reduce the amount of data that needs tobe sent and the power required. Embedded microprocessors in the smartsensor devices execute processes, for example, processes implemented insoftware code that implement the fog computing at a location proximalthe sensors, rather than through cloud computing by remote servers. Inthis manner, an improved, less-expensive more-expeditious approach todata processing and performance monitoring is provided. Equations usedto perform the metric calculations can be derived from years ofmeasuring and verifying solar asset performance.

The Denowatts™ calculation metric accounts for a number ofperformance-related parameters. In some embodiments, such parameters caninclude on or more of irradiance, temperature, static and dynamic systemderating, or other parameters indicative of system performance. TheDenowatts™ calculation metric incorporates various on-site variables,system specifications and derived data for typical operating conditions.In some embodiments the on-site variables can include POA irradiance. Insome embodiments the on-site variables can include sensor temperature.In some embodiments, the system specifications can include DC standardtest condition (STC) rating of a DC to AC inverter maximum AC output. Insome embodiments, the derived data can include static derate, which inturn can comprise observed DC to AC derating. In some embodiments, thederived data can include dynamic derate as observed inverter efficiencycurve data. As described herein, various modes of operation can beemployed, depending on, among other things, the time of day. Forexample, while operating in a “day” mode, the smart sensor devices canperform the Denowatts™ calculation every minute using 5 second intervalsample data to deliver exceptional granularity and accuracy across abroad range of environmental conditions. At other times of the day, thesample data interval, the Denowatts™ calculation interval, and thetransmission interval can be lengthened so that they are performed lessfrequently, and therefore consume less system power.

In some embodiments the smart sensor devices can be powered according toa number of different approaches. For example, they can be self-poweredby integrated energy harvesting circuits, such as one or more solarcells and one or more super capacitors, for a power source. In anotherexample, a battery source, for example a lithium battery pack, canoptionally be included to provide years of auxiliary power duringextended dark conditions when the solar based source may be unavailable.In other example embodiments, the power source can comprise a wiredpower source.

In exemplary embodiments communications between the smart sensor devicesand the receiver/gateway can utilize powerful 900 MHz Zigbee protocolwireless radio transceivers. Reliable transmission over 1500 feet can beobserved in urban environments when exemplary embodiments of the smartsensor devices employ integrated antennas. Further optional antennas canbe included to extend transmission over 2500 feet.

In exemplary embodiments the smart sensor devices can employ areceiver/gateway that can interface with a remote monitoring serviceusing standardized transmission protocols. In some embodiments, theMODBUS TCP protocol can be employed. In some embodiments,receiver/gateway can utilize 24V dc power and have Ethernetconnectivity. For example, in some embodiments, the system can operatein an always “on”, for example, via broadband, modem, cellular or wiredcommunications

In exemplary embodiments, one or more of the smart sensor devices can bemounted to an existing or potential solar array for the purpose ofdetermining energy resources and to monitor their production of anexpected power and energy output. In some embodiments, the smart sensordevice can be packaged and programmed to behave like a miniature solararray; however, instead of producing energy, it produces information. Insome embodiments, such information can be calculated according to theprocesses described herein, which, in turn, may then be used as areference point for determining solar performance verification orpotential solar performance of a solar array. In some embodiments, thesmart sensor devices can be self-contained, for example, each caninclude its own power source, wireless communication system, processingsystem, and data storage system.

In some embodiments, the smart sensor devices can be packaged in aweather-resistant container. In some embodiments, the container can bemounted to one or more solar array panels in such a manner thatirradiance sensors on the container are mounted or otherwise fixed to beoriented in a plane that is parallel to a plane on which the solarmodules or panels are arranged, so that the orientation of the sensor issuch that the sensors receive the same light, and at the sameorientation, as the solar cells of the solar panels.

In operation, the smart sensor devices in accordance with embodiments ofthe present inventive concepts can be configured to fixed weatherstations which are commonly used to collect and report weather data.Such conventional weather stations commonly produce only processed datarelated to sensors such as sun intensity and temperature. In contrast,systems and methods of the present inventive concepts can be configuredto additionally produce calculated metrics that represent the productionof an actual solar array, as described herein. In this manner, the smartsensor device can be considered to be a “smart and self-contained” unit.

According to the systems and methods of the present inventive concepts,the processing of data may further include calculating and accumulatinga total amount of Sun-Hours collected from the integral of irradiancedata, and storing and transmitting the total amount of Sun-Hours to thedata monitoring user. The accumulation may be used to ensure thatincident irradiance flux is recorded, even during power outages, suchthat the delivery of measurement and verification services ismaintained. The accumulated irradiance data can be used in the processof compiling an adjusted performance baseline which can address thequestion: “Is my solar array actually doing what it is modeled to do?”

Various exemplary embodiments of the present inventive concepts can begenerally characterized, according to the following: sensing,processing, transmitting, and form factor. Such categories are includedhere only for purposes of discussion, and embodiments are not thuslimited.

Referring to FIGS. 2A, 2B, 2C, 2D, 2E(1), 2E(2), 2E(3), 2F, and 2Gexemplary embodiments of a smart sensor device for performancemonitoring of a solar array having one or more solar panels aredepicted.

In some embodiments, a smart sensor device 11 in accordance with thepresent inventive concepts comprises one or more solar irradiancesensors 14, and one or more optional temperature sensor 20, mounted to adevice platform 22 or housing. In some embodiments, the device platform22 can comprise a primary platform 22 that can be coupled to a secondarydevice platform 24. In some embodiments, together, the primary 22 andsecondary 24 device platforms house the one or more solar irradiancesensors 14, the one or more optional temperature sensors 20, andadditional componentry employed for carrying out the processes of thepresent inventive concepts. In some embodiments, the primary deviceplatform 22 is constructed and arranged to be seated at a top of theneighboring solar array panels 16 to which the device is mounted, andthe secondary device platform 24 is constructed and arranged to beseated at a bottom of the neighboring solar array panels 16 to which thedevice is mounted. In some embodiments, the primary device platform 22,and, if employed, the secondary device platform 24 are configured to bemounted between edges of two neighboring panels 16 having a gap 18between them as seen in FIG. 2A

In some embodiments, for example referring to FIG. 2B, the smart sensordevice 11 may further include one or more of system processingelectronics 75, a power source 73, a communication transceiver 77 apower storage element 79 and a secondary circuit panel 81 for supportingthe devices and communications between them. In some embodiments, thesystem processing electronics 75 can include a processor, relatedinput/output electronics, volatile system memory and non-volatile systemmemory utilized for carrying out system processes. In some embodimentsthe power source 73 can comprise a battery pack or other source ofpower. In some embodiments, the communication transceiver can comprisecomponentry used for implementing wireless or wired communicationbetween the smart sensor device 11 and a remote receiver/gateway system.

In some embodiments, the system processing electronics 75 may bepositioned at the primary platform 22, the secondary device platform, orboth 22, 24. In some embodiments, a power source 75 may be positioned atthe primary platform 22, the secondary device platform 24, or both 22,24. In some embodiments, the communication transceiver 77 may bepositioned at the primary platform 22, the secondary device platform, orboth 22, 24. In some embodiments, electronic signals can be communicatedbetween components of the primary 22 and secondary 24 platforms via acable 26. In other embodiments, the electronic signals can becommunicated between components of the primary 22 and secondary 24platforms in a wireless arrangement.

In some embodiments, the smart sensor device 11 may further include adevice solar array 28. In some embodiments, the device solar array 28can be positioned at an upper surface of the primary platform 22, so asto be directly exposed in incident sunlight. In some embodiments, thedevice solar array 28 can be employed to provide a power source to thesmart sensor device 11. Energy absorbed by and converted by the devicesolar array 28 can be stored in a harnessed power storage element 79,for example a capacitor or a super capacitor. The energy stored in theharnessed power storage element 79 can in turn be used to power theoperations of the smart sensor device. In some embodiments the devicesolar array 28 and harnessed power storage element 79 can operate as theprimary power source for the smart sensor device 11. In someembodiments, the device solar array 28 and power storage element 79 canoperate as the sole power source for the smart sensor device 11. In someembodiments, the device solar array 28 can be used to re-charge thepower source 73, for example, the battery pack, for the smart sensordevice 11. In such an arrangement, the power storage element 79 may notbe needed. In embodiments where the power storage element 79 isincluded, the power storage element 79 may be positioned at the primaryplatform 22, the secondary device platform, or both 22, 24.

In some embodiments, operations related to sensing can includeoptionally utilizing output signals of one or more solar irradiancesensors 14, and output signals of the temperature measurement sensor 20.In some embodiments, the solar irradiance sensor 14 may comprise asilicon photodiode, for example a pyranometer or other suitable device,which operates to measure sunlight intensity. Such solar irradiancesensors 14 can be optionally configured to monitor various bandwidths ofsunlight intensity. For example, in some embodiments, a single solarirradiance sensor 14 can be configured to measure sunlight intensity ata specific wavelength or over a range of wavelengths. Similarly, in someembodiments, multiple solar irradiance sensors 14 a, 14 b, as shown inFIGS. 2B, 2D, 2F can be configured to measure sunlight intensity at aspecific wavelength or over a range of wavelengths.

In some embodiments, a first solar irradiance sensor 14 a can beconfigured to measure sunlight intensity at a first wavelength and asecond solar irradiance sensor 14 b can be configured to measuresunlight intensity at a second wavelength. In some embodiments, furthersolar irradiance sensors, for example, third and fourth, or more, solarirradiance sensors 14 c, 14 d, as shown in FIG. 2G, can be configured tomeasure sunlight intensity at third and fourth, or more, wavelengths.

In some embodiments, a first solar irradiance sensor 14 a can beconfigured to measure sunlight intensity at a first range of wavelengthsand a second solar irradiance sensor 14 b can be configured to measuresunlight intensity at a second range of wavelengths. In someembodiments, further solar irradiance sensors, for example, third andfourth, or more, solar irradiance sensors 14 c, 14 d, can be configuredto measure sunlight intensity at third and fourth, or more, ranges ofwavelengths.

In some embodiments, a first solar irradiance sensor 14 a can beconfigured to measure sunlight intensity at a first wavelength and asecond solar irradiance sensor 14 b can be configured to measuresunlight intensity at a second range of wavelengths.

In some embodiments, a first solar irradiance sensor 14 a can beconfigured to measure sunlight intensity at a first wavelength or firstrange of wavelengths and a second solar irradiance sensor 14 b can beconfigured to measure sunlight intensity at a second wavelength orsecond range of wavelengths, wherein the first and second wavelength orfirst and second range of wavelengths are substantially equal. In such aconfiguration, redundancy of the solar irradiance sensors 14 a, 14 baccommodates certain situations where such redundancy to help tomaintain system efficacy. For example, redundancy of the solarirradiance sensors 14 a, 14 b can maintain system efficacy where one ofthe multiple irradiance sensors has a foreign substance blocking itsouter surface, or where one of the multiple irradiance sensorsmalfunctions.

In some embodiments, the solar irradiance sensor 14 can be mounted in astandardized packaging such that sunlight can be measured in the Planeof Array (POA) or at an angle normal to the face of a solar module 16 orpanel surface to which the smart sensor device 11 is mounted. In thismanner, the solar irradiance sensor 14 experiences sunlight exposurethat is similar to the exposure experienced by the neighboring solarmodules 16. For example, one or more solar irradiance sensors 14 can bepositioned on the smart sensor device 11, in turn positioned on thesolar panels 16, as shown in FIG. 2A. In this manner, the orientation ofthe solar irradiance sensor 14 is substantially orthogonal to the planein which the top surfaces of the solar panels 16 lie. Accordingly, thesolar irradiance sensor 14 is equally subject to the same environmentalfactors as the solar panels 16, such environmental factors as shade,snow, soiling by leaves, dirt, bird droppings, and the like.

In some embodiments, for example in a case where multiple, for exampletwo or more, solar irradiance sensors 14 are employed, such as in theembodiments of 2D, 2E, 2F and 2G, an average of the irradiance valuesreceived by the multiple irradiance sensors can be calculated to providethe irradiance measurement. In such an embodiment, the averageirradiance value received by the multiple irradiance sensors known to befunctioning properly can be calculated and used to provide theirradiance measurement.

Referring to the exploded perspective view of FIG. 10A, in someembodiments, a solar irradiance sensor 14 may comprise a diffuser 116,one or more photodiodes 114, and supporting electronics 110. Thediffuser 116 is configured to receive incident light and present theincident sunlight to one or more light capturing devices, for example,photodiodes. The one or more photodiodes 114 are configured to convertthe received and diffused incident sunlight into a voltage or currentsignal. The supporting electronics are provided on a circuit board 110.In some embodiments, for example in the embodiments of FIGS. 2D, 2E, 2Fand 2G, the circuit board 110 may be configured to have mounted theretoone or more solar irradiance sensors 14, each associated with aphotodiode 114. In some embodiments where multiple solar irradiancesensors 14 are included, the multiple photodiodes 114 can each have adifferent and unique frequency response characteristic. Such amultiple-photodiode configuration can allow for the mathematicalcombination of the sensitivity of multiple irradiance sensors 14, suchas averaging, across a broad light spectrum to reduce spectral error, togive results comparable to those provided by a broadband thermopile,while using a combination of components that are relatively simpler indesign and sensitivity, and therefore cost.

In some embodiments, the circuit board 110 is constructed and arrangedto include a connector pattern, referred to herein as a photodiode pad112, arranged to accept multiple types and configurations of photodiodes114. Such photodiodes can include photodiodes formed of, in variousexamples, amorphous silicon, indium gallium arsenide, gallium arsenidephosphide, and the like. Such photodiodes of different types can be ofdifferent configurations, sizes, and lead footprints, which can beaccommodated by the photodiode pad 112 arrangement. In this manner, asingle circuit board 110 can be manufactured in a manner so as to becompatible with solar irradiance sensors 14 that employ any of a numberof different photodiodes. This eases the burden on manufacturing costs,and allows for a single circuit board platform 110 to be adaptable to arange of different applications. An optimal photodiode 114 for a solarirradiance sensor can be selected for a given application and applied toa standardized circuit board 110.

In some embodiments, each irradiance sensor 14 includes a diffuser 116and a corresponding single photodiode 114 mounted to the photodiode pad112. As shown and described herein in connection with the embodiments ofFIGS. 2C, 2D, 2F, and 2G, for example, multiple irradiance sensors 14 a,14 b can be configured on the same circuit board 110 or otherwiseincluded in the same smart sensor device 11. Assuming correspondingphotodiode pads 112 a, 112 b are included with each solar irradiancesensor 14 a, 14 b, then, in some embodiments, different types ofphotodiodes 114 a, 114 b may be positioned on the different photodiodepads 112 a, 112 b. As described herein, assuming each photodiode 114 a,114 b is sensitive to a different wavelength of light or a differentspectrum of wavelengths of light, then those different wavelengths orspectrums of wavelengths can be considered when computing an irradiancevalue for the smart sensor device 11. In addition different types ordifferent geometric arrangements of diffusers 116 a, 116 b can beemployed for similar reasons.

Further, in a case where multiple solar irradiance sensors 14 a, 14 b,are included in the smart sensor device, and the same type of diffuser116 a, 116 b, and photodiode 114 a, 114 b is employed, such aconfiguration allows for the capability to remotely manage an individualsolar irradiance sensor 14 a, 14 b that may become inoperative orinaccurate due to soiling and sensor drifting. In such a case, the smartsensor device 11 may be re-programmed, for example, to inactivate thebad sensor, or to bias or weight the sensor reading of an operationalsensor over that of an underperforming sensor.

As described herein, photodiode pad 112 comprises a location at thecircuit board 110 at which the photodiodes 114 are electricallyconnected to the circuit board 110 and supporting electronics 111.Referring again to FIGS. 10A, 10B, 10C, 10D and 10E there are depictedin exploded perspective view, cross-sectional view and planar view,exemplary embodiments of solar irradiance sensor devices in accordancewith the present inventive concepts. As seen in FIG. 10A, the circuitboard 110 for mounting in or on device platform 22 may contain auniversal photodiode pad 112 (depicted in more detail in FIG. 10E) thatallows the electrical connection of four or more different types ofphotodiodes 114 to the circuit board 110. Depicted in FIG. 10A is anexample of one type of photodiode, namely, an Amorphous Silicon (a-Si)photodiode. As seen in FIGS. 10B, 10C and 10D photodiodes 114 can be ofvarious shapes and sizes, including surface mount photodiodes, thru-holemount photodiodes, and others. Diffuser 116 is a universal diffuserwhich covers photodiodes 114 for measuring various light attributes withcap 118 providing covering protection. In some embodiments, and withreference to FIG. 10B, the diffuser 116 has a sufficient inner heightD_(H) and a sufficient inner width D_(W) so that is of sufficient sizeto house different types of system-compatible photodiodes 114 a, 114 b,114 c of different heights and widths. In particular, the inner heightD_(H) of the diffuser 116 is selected to be sufficient for thesystem-compatible photodiode of the greatest anticipated height, in thisexample, the photodiode of FIG. 10B. At the same time, the inner widthD_(W) of the diffuser 116 is selected to be sufficient for thesystem-compatible photodiode of the greatest anticipated width, in thisexample, the photodiode of FIG. 10C. As seen in FIG. 10E the surface ofuniversal photodiode pad 112 includes various electrical contactlocations L1. L2, L3, L4 for mounting various photodiodes 114. Forexample, an a-Si surface mount photodiode could be mounted in pad areaL1, an InGaAs thru-hole mount photodiode could be located in pad areaL2, an a-Si thru-hole mount photodiode could be located in pad area L3,and a GaAsP thru-hole mount photodiode could be located in pad area L4.

With reference to FIG. 10F, in some embodiments, an irradiance sensor 14includes a diffuser 116 and multiple photodiodes 114 a, 114 b mounted tothe photodiode pad 112 and positioned under the same diffuser 116. Inthe case of multiple photodiodes 114 a, 114 b mounted under the samediffuser 116, in some embodiments, the multiple photodiodes 114 a, 114 bare of the same type and are provided for redundancy. Accordingly,detection electronics remote the smart sensor device 11 can remotelydeactivate an underperforming one 114 a of the photodiodes and activatea redundant operational one 114 b of the photodiodes to thereby expandthe longevity of the smart sensor device 11. In the case of multiplephotodiodes 114 a, 114 b mounted under the same diffuser 116, in someembodiments, the multiple photodiodes 114 a, 114 b can be of differenttypes and are provided for sensing different wavelengths or ranges ofwavelengths of sunlight incident on the shared diffuser 116.

In some embodiments the primary platform 22, the secondary deviceplatform 24, or both 22, 24. may include one or more electricalconnectors 93 (see FIG. 2F, for example) for the attachment of athird-party sensor 91 (see FIG. 4), for example, a pyranometer,temperature sensor, or other weather measurement device for measuring,processing, and recording data in a manner similar to the solarirradiance sensor 14 or the temperature sensor of the smart sensordevice 11.

In some embodiments the use of a third-party sensor 91, such as apyranometer, may be used in the calibration process of the solarirradiance sensor 14 or the temperature sensor 20, or both. In such anembodiments, the third-party sensor 91 may operate as a referencemeasurement and allow the further improvement of device sensitivity forthe purpose of calibrating the sensors 14, 20. Such computation ofcalibration factors be completed on-board the smart sensor device 11 orremotely. Adjustments to the operating parameters of the device,including calibration factors, may be made locally or remotely to thesmart sensor device 11.

FIGS. 11A, 11B and 11C are top-perspective, side and top viewsrespectively of an embodiment of the primary device platform 22, inaccordance with the present inventive concepts. In this view, it can beseen that the primary device platform 22 has a width 22W in thedirection of the x-axis, a length 22L in the direction of the y-axis anda height 22H in the direction of the z-axis. For purposes of thisembodiment, the width 22W of the primary device platform 22 isdetermined as its maximum width in the in direction of the x-axis. Forpurposes of this embodiment, the height 22H of the primary deviceplatform 22 is determined as its maximum height in the direction of thez-axis. In particular, the height 22H is measured from a lower surface122 at the underside of the primary device platform 22 at which theunderside primary device platform is configured to make contact with atop surface of a solar panel to which the primary device platform 22 isto be mounted to an uppermost surface of the primary device platform 22and any device components mounted thereto. In this example embodimentthe uppermost surface comprises the uppermost surface of the solarirradiance sensors 14, as the diffuser component of the sensors 14extends above a top surface of the chassis of the primary deviceplatform 22; therefore, the height 22H of the primary device platform 22in this case is measured as the distance between the lower surface 122thereof to a top surface of the solar irradiance sensors 14. In someembodiments, the width 22W of the primary device platform is 1.5 inches,the length 22L of the primary device platform 22 is 10 inches, and theheight of the primary device platform 22H, including the extension ofthe solar irradiance sensors 14 is 0.62 inches. In some embodiments, thewidth 22W of the primary device platform is 1.5 inches, the length 22Lof the primary device platform 22 is 10 inches, and the height of theprimary device platform 22H, including the extension of the solarirradiance sensors 14 is 0.5 inches.

With this explanation of terms in mind, in some embodiments, the width22W of the primary device platform 22 is greater than or equal to twotimes the height 22H of the primary device platform 22. Alternatively,in some embodiments, the width 22W of the primary device platform 22 isgreater than or equal to three times the height 22H of the primarydevice platform 22. Assuming such a ratio of width 22W to height 22H,the configuration of the primary device platform 22 is managed to have arelatively low profile. Accordingly, shadowing of solar cells ofneighboring solar panels 16 to which the primary device platform ismounted is mitigated or eliminated, and system efficiency is notadversely affected by the presence of the smart sensor device 11.

In some embodiments, the temperature measurement sensor 20 may comprisea thermocouple, or other suitable device, suitable for measuring ambienttemperature. As seen in the embodiments of FIGS. 2B, 2C, 2D and 2E(2),and 2H and in drawings of other embodiments, the temperature sensor 20,can be attached to the smart sensor devices 11, either on the primarydevice platform 22 as seen in embodiment of FIG. 2C or on the secondarydevice platform 24, to allow for a measurement of ambient airtemperature to be taken at a position that is out of direct sunlight.The measurements taken by the smart sensor device components can beutilized to determine the solar intensity and the calculated solar celltemperature, two variables from which a determination of expected poweroutput of the modules 16 can optionally be determined.

In some embodiments, the composition of the primary platform 22 and thesecondary platform 24 comprises a molded polycarbonate material. In someembodiments, each platform 22, 24 includes a base and a cap thatencompass a volume therebetween. The base and cap can be sealed relativeto each other to resist entry of moisture. Componentry including thecircuit board 110, sensors 14, 20, device solar array 28, power source73, processor 75, capacitor 79 and transceiver 77 are positioned in thesealed volume of the platform 22, 24. Gasketing can be positioned at theinterface of the diffuser of the solar irradiance sensor 14 and theupper surface of the primary device platform 22 to resist entry ofmoisture through that interface. In some embodiments the material of theprimary and secondary platforms 22, 24 is transparent to the wavelengthsof incident sunlight. In this manner, heating of the smart sensor device11 can be mitigated. In addition, the use of transparent material allowsfor a pass-through of incident sunlight to the solar array 28 of thesmart sensor device 11 so as to optimize power generation by the solararray 28. Further, the use of transparent material allows for visualinspection of the componentry contained therein, which may include LEDvisual indicators.

Referring to FIG. 2D, in exemplary embodiments of the smart sensordevices that include both a primary device platform 22 and a secondarydevice platform 24, mounting rods 30 can be provided to allow device theprimary platform 22 to be mounted on at a first, upper, surface of thesolar array panels 16 (see FIG. 4), while the secondary platform 24 canbe spaced apart from the primary device platform 22 and mounted on to asecond, opposing, lower side of the solar array panels 16. In someembodiments, the mounting rods 30 can be coupled between the primaryplatform 22 and secondary platform 24 using bolts 30A, mating nuts 30Band washers 30C, as shown in FIG. 2E(2). The bolts 30A are positionedthrough corresponding openings 31 in the primary and secondary platforms22, 24. The mounting rods 30 and cable 26 are sufficiently narrow so asto fit in the gap 18 present between neighboring solar panels 18 towhich the smart sensor device 11 is mounted. At the same time, theprimary and secondary device platforms 22, 24 and washers 30C aresufficiently wide so they overlap neighboring panels 18.

FIG. 2H is a perspective view of an embodiment of the smart sensordevice 11 in accordance with the inventive concepts. In the embodimentof, FIG. 2H the smart sensor device 11 includes only the primaryplatform 22 and does not include the secondary platform. In a mannersimilar to the embodiment depicted in FIG. 2C, the primary platform 22of the embodiment of FIG. 2H can include all components required for thesensing, processing and transmission operations, and therefore, thesecondary platform is not required. With reference to FIG. 2C, suchcomponents included in the primary platform 22 can include one or moreof the solar irradiance sensor 14, the device solar array 28, the powersource 73, the processor 75, the transceiver 77, the capacitor 79, andthe circuit board 81, 110. Coupling mechanism 30 in this embodimentincludes washers 30C of sufficient width to communicate with undersidesof neighboring solar panels 16. Other mechanical coupling mechanisms areequally applicable to the present inventive concepts.

In some embodiments, for example in the embodiments depicted at FIGS.2E(1)-(3) a cable gland 27 can be coupled to a wall of the housing ofthe primary or secondary device platforms to serve as a moisture-proofvia for wire or cable systems, for example, power cables, Ethernetcables, or custom communication signal cables.

Referring to FIGS. 3A and 3B, an exemplary embodiment is shown wherein asmart sensor device 11 in accordance with the present inventive conceptsis mounted between a pair of solar panels 16. In these depictions, itcan be seen that the smart sensor device 11 s constructed and arrangedto be positioned between neighboring panels, with interfering with theiroperation, or minimizing interference with their operation. It can beseen that a typical solar panel 16 includes a frame 16B that extendsaround the perimeter of the panel, and solar cells 16A at the interiorof the frame 16B. The panel frame 16B is typically 1″ in width, and theprimary device platform 22 is preferably of a width 22W so that itcontacts exclusively the frame 16B and avoids interfering with the solarcells 16A when mounted. Neighboring solar panels are typically arrangedto have a gap of greater than 0.25″ to allow for thermal expansion andless than 1.5″ to optimize density.

Apparatus and methods for computing the Denowatts™ calculation metricwill now be described. Reference is made to the embodiment of FIG. 4Awhich provides a block diagram of an electronic system in accordancewith embodiments of the present inventive concepts. In the embodiment ofFIG. 4A, a smart sensor device 11 in accordance with embodiments of theinventive concepts includes one or more solar irradiance sensors 14generating an irradiance signal 15 and one or more optional temperaturesensors 20 generating a temperature signal 21. The irradiance signal 15and the optional temperature signal 21 are provided 50 to a processorthat is on-board the smart sensor device 11, in the sense that isco-located with the one or more solar irradiance sensors 14 and the oneor more optional temperature sensors 20 on the primary device platform22, secondary device platform 24, or both 22, 24. The on-board processor50 operates to periodically calculate cumulative irradiance values 61and Denowatts™ metric values 59 and stores the periodic values in astorage device 83 that is also on-board the smart sensor device 11, inthe sense that the storage device 83 is co-located with the one or moresolar irradiance sensors 14 and the one or more optional temperaturesensors 20 on the primary device platform 22 secondary device platform24, or both 22, 24. A data transmission system 65 periodically transmitsthe stored values to a remote receiver 67. The receiver 67 system mayoptionally include a gateway 69 to the Internet and related availablestorage facilities 71.

In some embodiments, an irradiance value is calculated 61 as acumulative value of a total irradiance received over a time interval. Insome embodiments, an output of the solar irradiance sensor 14 is in theform of an irradiance voltage signal 15 that varies in accordance withthe intensity of sunlight received by the sensor 14. The irradiancevoltage signal is input to the on-board processor 50 for calculating acumulative irradiance value 61, based on the irradiance voltage signal15. In some embodiments, a gain and an offset value are applied to thevoltage signal received by the processor to provide an irradiance value.In such embodiments, a generally linear relationship exists between thevoltage signal and the computed irradiance measurement Irr. Theirradiance measurement Irr is computed by the processor periodically,for example every 5 seconds, and the collection of computed irradiancemeasurements Irr are stored by the processor for further processing.

In some embodiments where two or more solar irradiance sensors 14 areincluded and actively used, the voltage signals from each sensor canfirst be averaged to provide an average irradiance value. The averageirradiance values are then compiled and used to generate the computedirradiance measurement Irr.

In other embodiments, as the voltage signals from each sensor can beweighted with respect to each other, and the weighted voltage signalsused to generate the computed irradiance measurement Irr. For examplethe voltage signals can be weighted depending, for example, on the sizeof solar irradiance sensors 14, depending on the composition ortechnology of a given solar irradiance sensor 14 or depending on theknown or suspected state of one or more of the sensors 14.

In the case where multiple irradiance sensors are deployed to measurewavelengths or ranges of wavelengths, the signals produced by thesensors 14 can be weighted, or factors applied, so that accuratecombined value is provided.

In some embodiments, calibration of the solar irradiance sensorconfiguration can be completed by comparing the sensors 14 againstcalibrated, third-party reference sensors of similar spectralabsorption.

In some embodiments, the computed irradiance measurements Irr arefurther processed to periodically compute a cumulative irradiance valueCumulative Irradiance. In some embodiments, this value can be computedas follows:

${{Cumulative}\mspace{14mu} {Irradiance}} = {\sum_{1}^{n}( \frac{Irr}{\frac{1}{n}(3600)(1000)} )}$

In this relationship, n represents the time sample interval, in terms ofseconds and Irr represents the computed irradiance measurement providedby the solar irradiance sensor. Cumulative Irradiance is calculated interms of sun-hours (1000 W/m²) (1 hour) and is representative of the sumof irradiance measurements over the course of an hour.

In this manner, the Cumulative Irradiance can be computed, in someembodiments of the present inventive concepts using exclusivelyprocessing of the output signals of irradiance sensors 14. Whileconventional approaches utilize a temperature measurement, for exampleusing a thermocouple, for the calculation of cumulative irradiance,embodiments of the present inventive concepts do not require such atemperature measurement, but instead can rely exclusively on the outputof irradiance sensors.

As described herein the Denowatts™ metric value is representative of asimulated energy generation value. In some embodiments, the Denowatts™metric value accounts for irradiance, temperature, system size, staticsystem derating and dynamic system derating to provide a performancemetric against which the performance of the solar collection systembeing monitored by the smart sensor device 11 can be gauged. In someembodiments, the Denowatts™ metric value is periodically calculatedon-board the smart sensor device 11, which contains processing powersufficient to perform such computations. Denowatts™ metric values arestored and periodically transmitted to a receiver station. In thismanner, raw irradiance data and, in some cases, raw temperature data,are processed locally using power-efficient processing equipment, andthe number and duration of power-hungry transmission operations to thereceiver station are minimized.

In some embodiments, the Denowatts™ metric values are periodicallydetermined as follows:

${{Denowatts}^{}\mspace{11mu} {metric}} = {\sum_{1}^{n}{( \frac{{{Irr}({Pdc})}( {1 + {\alpha ( ( {{Tcell} - 25} ) )}} )}{( \frac{1}{n} )(8600)(1000)} )( {{Derate}\mspace{14mu} {Factor}} )}}$

wherein:

${{Denowatts}^{}\mspace{11mu} {metric}} \leq {{Pac}/( {\frac{1}{n}*3600} )}$ELSE${{Denowatts}^{}\mspace{11mu} {metric}} = {{Pac}/( {\frac{1}{n}*3600} )}$

and wherein:n: Time sample interval (seconds)Irr: Computed Irradiance Measurement (computed above)Pdc: DC Power Rating of the solar arrayPac: Maximum Output AC Power Rating of the solar array

α: Reference Module Temperature Coefficient (Power)

Tcell: Calculated Solar Cell Temperature may be calculated as

Tcell=(Tdevice)(δ(Irr)+ε)

wherein:

-   -   Tdevice: Device temperature recorded on the device platform    -   δ and ε: calculated constants related to a reference cell

Static and Dynamic Derate Factors

Derate Factor=β(γ)

wherein:

β: Static Derate Factor

γ: Dynamic Derate Factor described by one or more polynomial equation(s)derived from the operating efficiency of a reference inverter and othersystem characteristics relative to irradiance conditions.

With reference to the flow diagram of FIG. 4B, and as described herein,the Denowatts™ metric calculation, referring to item 142, the parameterPdc takes into account the size of the solar collection system beingmonitored. This is typically a known reference item for the system beingmonitored.

Referring to item 144 of FIG. 4B, the Computed Irradiance MeasurementIrr, as measured by the one or more solar irradiance sensors 14 of thesmart sensor 11 takes into account the amount of solar light energyincident on the monitored solar collection system. As described herein,the Computed Irradiance Measurement Irr can be determined by theprocessor 50 in response to the output signals of the irradiance sensors14.

Referring to item 146 of FIG. 4B, an adjustment is made for theoperational efficiency of the monitored solar collection system based onthe measured temperature Tcell of the device 146, which in essence is aconverted temperature measurement Tdevice taken by the temperaturesensor 20 of the smart sensor 11, and which takes into account theComputed Irradiance Measurement Irr. For example, it is known that cellsof a solar collection system operate with higher efficiency at lowertemperatures; this measured temperature Tcell takes this into account.

Referring to item 148 of FIG. 4B, an adjustment is made for the staticderate factor β of the monitored solar collection system. The staticderate factor is a known factor for the system and takes into accountpower losses expected in the solar array, for example losses arising asa result of DC to AC conversion. Typically, the static derate factor βis on the order of about 0.9.

Referring to item 150 of FIG. 4B, an adjustment is made for the dynamicderate factor γ of the monitored solar collection system. The dynamicderate factor γ varies in response to irradiance Irr, and the responseis typically non-linear. The dynamic derate factor γ relates to theefficiency of the system inverter used for DC to AC conversion in themonitored solar collection system. When operating low light levels, thesystem inverter tends to be less energy efficient than when operating athigher light levels. With reference to FIG. 12, the non-linearefficiency of a system inverter is charted in response to systemirradiance Irr. In the example of FIG. 12, the behavior of systeminverter efficiency (y) is graphed in response to irradianceapproximates to the following polynomial:

y=−3E−13x ⁴+1E−9x ³−1E−6x ²+0.0005x+0.879

This formula is merely an example of the behavior of the dynamic deratefactor and other non-linear approximations, and linear approximations,may equally apply to the determination of dynamic derate factor γ asused herein. Accordingly, the dynamic derate factor accommodates forsystem non-linear behavior, for example non-linear behavior in monitoredsystem inverter for use in the calculation of the Denowatts™ metric.Consideration of dynamic derate factor in this manner provides for anexceptionally accurate modeling of the expected behavior of the modeledsolar system. Increased accuracy from the use of the dynamic deratingimproves the accuracy at lower light levels and variable light levelsrelative to contemporary techniques which lose considerable accuracy atlower and variable light levels.

Referring to item 152 of FIG. 4B, the individual Denowatts™ metricvalues are accumulated, and periodically computed as a cumulativeDenowatts™ metric for the system.

Under certain conditions, the thus computed cumulative Denowatts™ metricvalue may be determined to exceed the expected maximum output AC powerrating of the solar array Pac. In such cases, the cumulative Denowatts™metric value way be reduced to the expected maximum.

Readings may be then formatted into a data form that can be wirelesslytransmitted to a receiver 67 and internet gateway 69 as depicted in FIG.4. Additional features of the processor 50 can include the ability to beremotely programmed, including information related to sensor calibrationconstants and solar energy system characteristics, including ACnameplate value. In some embodiments, the processor can also beconfigured to store interval data as well as a cumulative output value.In some embodiments, the processor can be constructed and arranged tomanage the power performance requirements of the smart sensor device inorder to minimize smart sensor device energy usage and battery storagerequirements and is suitable for on-board processing of data to minimizethe amount of data transmitted to off-site software services. Inaccordance with embodiments of remote programmability, the transmissionsystem 65 can comprise a receiving system suitable for receivingwireless or wired signals from an off-board or remote source.

The generating and reporting of the Cumulative Irradiance value allowsfor the measurement and recording of the available solar resource. Thisin turn allows for the calculation of the weather adjusted generation asmodeled by a baseline energy simulation such as PVSyst, PVWatts, andothers. By adjusting the amount of available irradiance, as measured inSun-Hours, the expected energy generation may be adjusted linearly toanswer a critical solar array owner's question “Is my solar arrayperforming as it was expected to perform based on my baseline model?”.An additional feature for generating and reporting Cumulative Irradianceon the smart sensor device 11 is that during times of external power orcommunications outages, the measurements and process continue to recordthis critical information.

The generating and reporting of the Cumulative Denowatts™ metric permitsthe measurement and recording of the reference array energy generationin order to calculate a comparable baseline. By comparing the actualsolar array energy generation with the Cumulative Denowatts™ metricanswers a solar array owner's question “Is my solar array performing aswell as it could be relative to other similar solar arrays?”. Anadditional feature of generating and reporting Cumulative Denowatts™metric on-board the smart sensor device 11 is to ensure that in times ofexternal power or communications outages that the measurements andprocess continue to record this critical information.

Exemplary embodiments related to transmitting can optionally include aradio (RF) frequency and/or cellular transmitter. In exemplaryembodiments, the RF transmitter can be configured to employ a frequencythat is best suited for long-distance, structural penetration (toinclude concrete and steel), and low power consumption. In exemplaryembodiments, the smart sensor devices 11 can also incorporate an RFreceiver unit 67, which may stand alone or be incorporated into aninternet gateway equipment component. In exemplary embodiments, the RFreceiver unit 67 can include both as RS-485 and Ethernet options fordelivering the data from the smart sensor devices to an array ofinternet gateways 69 which are commercially available to connect to theinternet. A 2-way system can be employed that allows for remote firmwareupdates as well as remote calibration, system information updates, andan instantaneous readout mechanism for near instantaneous readings, forexample, during peak energy demand periods on the utility grid. Inexemplary embodiments, referring to FIG. 2F, optional antenna 25 andsupporting electronics can be included to extend transmission over 2500feet.

Exemplary embodiments related to form factor can optionally include auniversal mounting configuration with modules, a solar power charger forlong-term augmentation of the self-contained power supply, integratedsensors that allow a standardized installation, or an onboard antennaefor long-range wireless transmission (RF or cellular).

Exemplary embodiments related to the usage of generated data include aratio that is defined by the solar power system recorded generationoutput (“Numerator”) divided by the smart sensor device Output value(“Denominator”) during congruous time intervals. Such a ratio can be thebasis for a smart sensor device Performance Index Factor which is usedto track and communicate performance. The smart sensor devicePerformance Index Factor may be defined as the Solar Array ActualGeneration divided by the smart sensor device Output cumulated during aconcurrent time period and may be calculated as follows:

Factor=Actual Generation/Device Output

In a typical day, much like the solar array on which exemplaryembodiments of the smart sensor devices can be implemented, the smartsensor devices can have different time-based “mode of operation”. Forexample, the smart sensor devices can be configured to “sleep” at nightto conserve power and to “wake up” at a time when solar energy can begenerated. During night conditions, the smart sensor devices can logdata less frequently, for example at a frequency of once per hour andtransmit less frequently, for example every 6 hours. In someembodiments, during a “sleep mode”, the Denowatts™ calculation is notcalculated when the intensity level is determined to be below 10 w/m².During twilight conditions (10-40 w/m²) the smart sensor devices can“wake up” and sample data at a rate that is reduced relative to fullyoperational mode, yet is greater than sleep mode, for example every 30seconds. Data can be transmitted at a similarly reduced rate, forexample every 6 minutes. At such a twilight light level a typicalinverter will begin to generate energy. During high sun conditions thesmart sensor device can sample data at a higher rate, for example every5 seconds and transmit data at a higher rate, for example every 5minutes. As evening twilight conditions return, the smart sensor devicecan wind down and eventually return to sleep mode until the nextmorning. The frequency of sampling, logging and transmission of data canvary, depending on the data resolution required, and depending on thetype of transmission system, as identified in the chart of FIG. 8.

In exemplary embodiments, remote management of the smart sensor devices11 can be provided such that highly-reliable and accurate service can bedelivered. Remote management allows for data quality management,calibration and configuration changes and remote diagnostics, includinghardware resets, such that field maintenance is minimized. Utilizationof the smart sensor devices 11 in remote management mode allows forhassle-free Data as a Service (DaaS) coupled with the accuracy ofon-site calibrated sensors.

Referring now to FIG. 5, an exemplary embodiment depicts the data logicand data flow described herein. Environmental sensoring data 40, assetspecification data 42 and reference specification data 44 are determinedand recorded 46. In some embodiments, asset specification data 42 caninclude one or more of the following: DC STC capacity, AC Rated and ACMax information. In some embodiments, reference specification data 44can include one or more of the following: static derate, dynamic derate(included inverter efficiency curve and others), modulepower/temperature coefficients and module degradation coefficients.Denowatts™ calculations and cumulations 48 are computed by the embeddedprocessor 50. Signals from POA irradiance sensors 52 and temperaturesensor 54 are provided to signal conditioning circuitry 56 and fromthere to embedded processor 50. Embedded processor 50 provides dataoutput in the form of average POA irradiance 57, average celltemperature 58, cumulative Denowatts™ metrics 59, and cumulativeIrradiance values are determined and recorded.

Referring to FIG. 6, there is depicted the various communication modesdescribed above. In various embodiments, data output as depicted in FIG.5, can be transmitted by wireless RF, hard wired, and cellular, or byusing other suitable communication mechanisms. In the embodimentdepicted in FIG. 6, the wireless RF is received by receiver/gateway 60and communicated to local area network 62, which in turn can provide thereceived information to third party monitoring entity 64 and dataservices supplying entity 66. Local area network 62 can also receive thedata output via hard wiring. Cellular network 68 can also receive thedata output and similarly provide the received information to thirdparty monitoring entity 64 and supplier 66.

As depicted in FIG. 6, third party monitoring entity 64 and dataservices supplying entity 66 can provide via similar transmissionmediums 63 to receiver/gateway 60 configuration adjustment data suchthat one or more of the following can be adjusted at the smart sensordevice: component calibration, simulation parameters, instruction code,and sensor drift of an irradiance sensor of the smart sensor device.Instruction code of the processing system of the smart sensor device,which is discussed in more detail herein, can then receive fromreceiver/gateway 60 the configuration adjustment data to update thesmart sensor device. An adjustment of sensor drift of the irradiancesensor can include updating irradiance sensor voltage gain and offset.

Referring to FIG. 7A, there is depicted the various power supplyingapproaches as described above. Device solar array 28, considered primarycells, provide power to energy harvesting circuits 70, which in turnprovide power harvested to a harvested power storage device, for examplesuper capacitor 72. In some embodiments, 99% of the power consumed bythe wireless RF transceiver 74 is provided by harvested power storagedevice 72 as discussed in conjunction with FIG. 6.Processor/transceiver/primary cells 73 can include a battery pack thatcan provide the remaining 1% of the power for the operation of thewireless RF transceiver 74. In some embodiments the battery pack caninclude lithium battery cells. When the data output transmissiondepicted in FIG. 6 is wired or cellular 76, 100% of the power can besupplied from an external DC power source 78. Receiver/gateway 80 thatreceives the data output is typically 100% supplied from general powersupply 82.

In exemplary embodiments the smart sensor device 11 can be deemedself-powered. As noted in FIG. 7A, in some embodiments, the smart sensordevice 11 can include energy harvesting circuits 70 and storagecircuitry which includes a harvested power storage device, such as supercapacitor 72. Appropriate programming and power allocation can enableoperation of the smart sensor device 11 without the need of an externalpower source or battery source. In such an embodiment, the smart sensordevice 11 can operate under its own locally generated power in order toprocess the Denowatts™ calculation, obtain its result and providewireless communications with the reciever/gateway. Such self-poweredoperation eliminates the need to connect the smart sensor device to alocally wired power supply or battery supply, reduces cost, and ensuresthat energy generation potential can be continually measured andrecorded, even in the absence of power by the solar array. In someembodiments the solar sensor device may record the amount of power“lost” due to the solar array being down. This can be important forenergy accounting purposes.

Referring to FIG. 7B, an exemplary embodiment of a power arrangement isdepicted. In this example embodiment, device solar array 28 harvestsenergy directly from sunlight and converts the energy to voltagepotential. Charge controller 82 coordinates power to voltage regulator86 and manages both the transfer and secondary power source switching,as well as the maximum power point tracking for solar cell 28 and supercapacitor 72. Lithium battery 84 is a stable power source configured toprovide backup power during periods without sunlight for energyharvesting. Super capacitor 72 provides storage for energy harvestedfrom solar cell 28, serving as short-term power storage for the energyharvesting circuit. Voltage regulator 86 regulates the voltages requiredfor the device circuits to operate. Processor 88 controls load switchingand is programmed to minimize device power requirements by switchingcircuits OFF during idle periods, loads 90 being the processing, sensorconditioning and communication circuits.

Referring to FIG. 8, there is depicted typical sampling, logs andreports for each of the daylight, twilight and dark (night-time) modesfor each of wireless RF, wired and cellular/Wi-Fi transmissions, asdiscussed above.

Exemplary embodiments of the present inventive concepts are describedherein with reference to flowchart illustrations and/or block diagramsof methods, apparatus (systems) and computer program products which maybe configured to provide executable instruction code that implements theprocesses/flowcharts/equations described herein. It will be understoodthat each block of the flowchart illustrations and/or block diagrams,and combinations of blocks in the flowchart illustrations and/or blockdiagrams, can be implemented by computer program instruction code knownto those skilled in the art.

The computer program instruction code may be stored in acomputer-readable medium that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablemedium produce an article of manufacture including instruction meanswhich implement the function/act specified in the flowchart and/or blockdiagram block or blocks.

For example, FIG. 9 provides a simplified block diagram depicting anexemplary processing system 201 formed in accordance with an exemplaryembodiment of the present disclosure. System 201 may receive data fromsignal source 208, both from within the solar sensor device and remotelyfrom third party monitoring entities and data services supplyingentities (as seen in FIG. 6), and may include a processor 202, memory203 coupled to the processor (e.g., via a bus 204 or alternativeconnection means), which may include instruction code 207 as disclosedherein, as well as input/output (I/O) circuitry 206 operative tointerface with the processor 202. The processor 202 may be configured toperform at least a portion of the methodologies of the presentdisclosure, illustrative embodiments of which are shown in the abovefigures and described herein.

It is to be appreciated that the term “processor” as used herein isintended to include any processing device, such as, for example, onethat includes a central processing unit (CPU) and/or other processingcircuitry (e.g., digital signal processor (DSP), microprocessor,programmable gate array, arrangement of discrete hardware or logicgates, etc.). Additionally, it is to be understood that the term“processor” may refer to more than one processing device, and thatvarious elements associated with a processing device may be shared byother processing devices. The term “memory” as used herein is intendedto include memory and other computer-readable media associated with aprocessor or CPU, such as, for example, random access memory (RAM), readonly memory (ROM), fixed storage media (e.g., a hard drive), removablestorage media (e.g., a diskette), flash memory, etc. Furthermore, theterm “I/O circuitry” as used herein is intended to include, for example,one or more input devices for entering data to the processor, and/or oneor more output devices for presenting the results associated with theprocessor.

The flowchart and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods and computer program products according to variousembodiments of the present disclosure. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instruction code, which comprises one or more executable instructionsfor implementing the specified logical function(s) described herein. Itshould also be noted that, in some alternative implementations, thefunctions noted in the block may occur out of the order noted in thefigures. For example, two blocks shown in succession may, in fact, beexecuted substantially concurrently, or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved. It will also be noted that each block of the block diagramsand/or flowchart illustration, and combinations of blocks in the blockdiagrams and/or flowchart illustration, can be implemented by specialpurpose hardware-based systems that perform the specified functions oracts, or combinations of special purpose hardware and computerinstructions.

While the inventive concepts have been particularly shown and describedwith references to exemplary embodiments thereof, it will be understoodby those skilled in the art that various changes in form and details maybe made herein without departing from the spirit and scope of thepresent inventive concepts as defined.

1. A device comprising: a platform constructed and arranged to bemounted to one or more solar array modules: one or more solar irradiancesensors on the platform configured to receive incident solar energy, theone or more solar irradiance sensors oriented on the platform so thatthe received incident solar energy is comparable to that received by thesolar array modules, the one or more solar irradiance sensors providingsolar irradiance signals in response to the incident solar energy; aprocessor on the platform, the processor configured to receive the solarirradiance signals and, in response, generating a performance referencemetric based on the solar irradiance signals, the performance referencemetric related to an expected performance of the one or more solar arraymodules to which the platform is mounted; a transmitter on the platform,the transmitter configured to periodically transmit the performancereference metric to a receiver; and a power source on the platform forpowering the processor and the transmitter.
 2. The device of claim 1,further comprising a temperature sensor that provides a devicetemperature signal and wherein the processor further generates theperformance reference metric based on the device temperature signal. 3.The device of claim 2, wherein the processor further generates theperformance reference metric based on a cell temperature signal that iscalculated in response to the device temperature signal and the solarirradiance signals.
 4. The device of claim 2, wherein the temperaturesensor generates the device temperature signal periodically.
 5. Thedevice of claim 1, wherein the processor further generates theperformance reference metric based on a dynamic derate value that iscalculated based on an efficiency function of an inverter of the solararray modules in response to the solar irradiance signals.
 6. The deviceof claim 5 wherein the efficiency function is non-linear.
 7. The deviceof claim 1, wherein the processor further generates the performancereference metric based on a static value that is calculated based on anestimate of expected power loss in the solar array modules.
 8. Thedevice of claim 1, wherein the processor further generates theperformance reference metric based on a cumulative irradiance value, thecumulative irradiance value being based on multiple ones of the solarirradiance signals accumulated over a time period.
 9. The device ofclaim 1, wherein the transmitter is further configured to transmit theperformance reference metric periodically in response to a mode ofoperation, the mode of operation being determined in response to a timeof day.
 10. The device of claim 9, wherein the mode of operation resultsin more frequent transmission during a time of day where more intensesun exposure is expected and results in less frequent transmissionduring a time of day when less intense or no sun exposure is expected.11. The device of claim 1, wherein the processor is further configuredto generate the performance reference metric periodically in response toa mode of operation, the mode of operation being determined in responseto a time of day.
 12. The device of claim 11, wherein the mode ofoperation results in more frequent generation of the performancereference metric during a time of day where more intense sun exposure isexpected and results in less frequent generation of the performancereference metric during a time of day when less intense or no sunexposure is expected.
 13. The device of claim 1, wherein a portion ofthe platform is constructed and arranged to be positioned on a topsurface of the one or more solar array modules, the portion having amaximum width in a first horizontal direction and having a maximumheight above the top surface in a vertical direction, wherein themaximum width is greater than or equal to two times the maximum height.14. The device of claim 1, wherein a portion of the platform isconstructed and arranged to be positioned on a top surface of the one ormore solar array modules, the portion having a maximum width in a firsthorizontal direction and having a maximum height above the top surfacein a vertical direction, wherein the maximum width is greater than orequal to three times the maximum height.
 15. The device of claim 1,wherein the platform comprises a circuit board and wherein solarirradiance sensors comprise a pyranometer, the pyranometer comprising: adiffuser for receiving incident solar energy, the diffuser comprising aninner chamber; and a photodiode positioned in the inner chamber forconverting the solar energy received by the diffuser into a currentsignal; wherein the inner chamber is of a sufficient height toaccommodate a maximum height of a photodiode selected among a pluralityof photodiode types; and wherein the inner chamber is of a sufficientwidth to accommodate a maximum width of a photodiode selected among aplurality of photodiode types.
 16. The device claim 16, wherein thecircuit board includes a photodiode pad including a plurality ofconductive pads for mounting any among the plurality of photodiodetypes.
 17. The device of claim 1, wherein the power source comprises asolar collector on the platform and a power storage element on theplatform for storing energy collected by the solar collector.
 18. Thedevice of claim 17, wherein the power storage element comprises a supercapacitor.
 19. The device of claim 17, wherein the solar collector andstorage element comprise an exclusive power source for the device. 20.The device of claim 17, further comprising a supplemental battery. 21.The device of claim 1, wherein the processor is configured to furtherreceive signals from a third-party sensor for calibration of the one ormore solar irradiance sensors.
 22. The device of claim 1, wherein atleast one of the one or more solar irradiance sensors is mounted betweena pair of solar array modules.
 23. The device of claim 1, wherein atleast one of the one or more solar irradiance sensors comprises apyranometer.
 24. The device of claim 1, wherein the one or more solarirradiance sensors are mounted on one side of the platform such thatprimary solar irradiance receiving surfaces of the one or moreirradiance sensors are substantially parallel to primary planes of thesolar array modules.
 25. The device of claim 1, further comprising atemperature sensor that provides a device temperature signal, whereinthe processor further generates the performance reference metric basedon the device temperature signal, and wherein the temperature sensor ismounted on an opposing side of the platform relative to the one side ofthe platform.